The Underestimated Role of Platelets in Severe Infection a Narrative Review

Quantitative changes in platelet count in response to different pathogens: an analysis of patients with sepsis in both retrospective and prospective cohorts

BACKGROUND

Thrombocytopenia is commonly observed in patients with sepsis and is an independent risk factor for poor prognosis. However, the changes of platelet count caused by different pathogens can vary significantly. Our study aims to evaluate the quantitative changes in platelet count in response to various pathogens.

MATERIAL AND METHODS

We retrospectively analysed data of 3044 patients with sepsis from Medical Information Mart for Intensive Care (MIMIC, 2008-2019) database and prospectively collected data of 364 patients with sepsis from our local cohort of the Shandong Bloodstream Infection and Sepsis Collaboration Study (SBISC, 2020-2022). Propensity score matching (PSM) was employed to control for baseline differences in variables, except for the causative pathogen.

RESULTS

Multivariate logistic analyses of both original and PSM populations identified Candida, Escherichia, Klebsiella, and Serratia species posing a higher risk for thrombocytopenia compared to others. Restricted cubic spline (RCS) curves showed L- or U-shaped associations between platelet count and 28-mortality with various cut-off values among different pathogens: ranging from 96 × 109/L in Candida species - 190 × 109/L in Klebsiella species.

CONCLUSION

Our present findings indicate a pathogen-specific effect on platelet count, highlighting the importance of monitoring thrombocytopenia in patients infected with above microorganisms. Clinicians need to consider pathogen-specific thresholds when intervene on platelet count.

Research progress of biomarkers in evaluating the severity and prognostic value of severe pneumonia in children

Pneumonia is a serious and common infectious disease in children. If not treated in time, it may develop into severe pneumonia. Severe pneumonia in children is mainly characterized by hypoxia and acidosis, often accompanied by various complications such as sepsis and multiple organ dysfunction. Severe pneumonia has a rapid onset and progression, and a high mortality rate. Biomarkers assist clinicians in the early diagnosis and treatment of patients by quickly and accurately identifying their conditions and prognostic risks. In this study, common clinical and novel biomarkers of severe pneumonia in children were reviewed, and the application value of biomarkers related to the severity and prognosis of severe pneumonia in children was evaluated to provide help for early identification and precise intervention by clinicians.

Prognostic Significance of Thrombocytopenia and Mean Platelet Volume in COPD Patients with Acute Exacerbations in ICU Settings

BACKGROUND Platelets have important modulatory effects on inflammatory and immune-mediated pathways. Thrombocytopenia is a critical condition that is frequently encountered in the intensive care unit (ICU) and increases mortality. This retrospective study of 472 patients admitted to the ICU with acute exacerbation of chronic obstructive pulmonary disease (COPD) aimed to evaluate thrombocytopenia and mean platelet volume (MPV) with prognosis and patient mortality. MATERIAL AND METHODS A total of 472 patients diagnosed with COPD according to GOLD criteria and hospitalized in the tertiary ICU between 1 April 2018 and 11 May 2021 were included in the study. Platelets were calculated by the impetance method and MPV was simultaneously calculated based on the platelet histogram. Patients with platelet count ≤100×10⁹/L and >100×10⁹/L and patients with MPV values <7 fl, 7-11 fl, and >11fl were compared in terms of mortality and prognosis. RESULTS The mortality rate in COPD patients with thrombocytopenia was high, at 61.5%. Thrombocytopenia (P=.002), high MPV (P=.006) Acute Physiology and Chronic Health Evaluation-2 (APACHE-II) score (P=.025), length of stay (LOS) in the ICU (P=.009), mechanical ventilation duration (P<.001), leukocytosis (P<.001), high Sequential Organ Failure Assessment (SOFA) score (P<.001), LOS in the hospital (P=.035), and hypoalbuminemia (P<.001) were significantly associated with mortality. CONCLUSIONS Thrombocytopenia, high MPV, high APACHE-II and SOFA scores, LOS in the ICU and hospital, duration of mechanical ventilation, leukocytosis, and hypoalbuminemia predict mortality in COPD patients. Since infection-sepsis, hypoalbuminemia, and hypoxia can worsen this situation, ensuring early infection control, providing albumin support, and preventing hypoxia contribute significantly to reducing thrombocytopenia and mortality.

The Potential Value of Mean Platelet Volume and Platelet Distribution Width as Inflammatory Indicators in Surgical Necrotizing Enterocolitis

Background

This study aims to investigate the potential significance of mean platelet volume (MPV) and platelet distribution width (PDW) in predicting surgical neonatal necrotizing enterocolitis (NEC) and establish the correlation between MPV/PDW levels and the severity/prognosis of NEC.

Methods

A retrospective study was conducted on a cohort of 372 patients diagnosed with NEC. The patients were categorized into two groups based on whether they underwent surgical therapy. Univariate /multivariate analysis were employed to compare the MPV and PDW between the two groups. Moreover, patients in surgical group were categorized into multiple subgroups based on intraoperative findings and postoperative prognosis, and the levels of MPV and PDW were compared among these subgroups.

Results

Of the 372 patients, the operative group exhibited significantly higher levels of MPV and PDW than the nonoperative group (P < 0.05). Logistic regression analysis revealed that MPV (OR = 4.895, P < 0.001) and PDW (OR = 1.476, P < 0.001) independently associated with surgical NEC. The analysis of the receiver operating characteristic (ROC) curve revealed that the area under the curve (AUC) was 0.706 for MPV alone, with a cut-off value of 11.8 fL. Similarly, the AUC was 0.728 for PDW alone, with a cut-off value of 16%. However, when MPV and PDW were combined, the AUC increased to 0.906 for predicting surgical NEC. In accordance with the intraoperative findings, the levels of MPV and PDW were found to be higher in the large area necrosis group than in the partial or mild necrosis group (P < 0.01). Furthermore, the MPV and PDW values in the death group were significantly greater than those in the survival group (P =0.040, P =0.008).

Conclusion

MPV and PDW may serve as potentially valuable indicators for determining the need for surgical intervention and predicting the prognosis of patients with NEC.

Characteristics and Risk Factors for Pediatric Sepsis

OBJECTIVE

Sepsis is considered a major cause of health loss in children and had high mortality and morbidity. Currently, there is no reliable model for predicting the prognosis of pediatric patients with sepsis. This study aimed to analyze the clinical characteristics of sepsis in children and assess the risk factors associated with poor prognosis in pediatric sepsis patients to identify timely interventions and improve their outcomes.

METHODS

This study analyzed the clinical indicators and laboratory results of septic patients hospitalized in the Pediatric Intensive Care Unit of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, China, from January 1, 2019, to December 31, 2021. Risk factors for sepsis were identified by logistic regression analyses.

RESULTS

A total of 355 children with sepsis were enrolled, with 333 children (93.8%) in the good prognosis group, and 22 children (6.2%) in the poor prognosis group. Among them, there were 255 patients (71.8%) in the sepsis group, and 100 patients (28.2%) in the severe sepsis group. The length of hospital stay in the poor prognosis group was longer than that in the good prognosis group (P<0.01). The levels of interleukin 1β (IL-1β) in the poor prognosis group were higher than those in the good prognosis group (P>0.05), and the platelet (PLT), albumin (ALB), and hemoglobin (Hb) levels were lower in the poor prognosis group (P<0.01). The IL-8 levels in the severe sepsis group were higher than those in the sepsis group (P<0.05). Multiple logistic regression analysis suggested that lower Hb levels, ALB levels, peak PLT counts, and higher IL-1β levels were independent risk factors for poor prognosis in children with sepsis.

CONCLUSION

Lower Hb, ALB, and PLT counts and elevated IL-1β are independent risk factors for poor prognosis in children with sepsis.

Acute primary CMV infection complicated by pneumonitis and ITP in young immunocompetent woman in a regional Queensland Hospital

We present the first published case of simultaneous pneumonitis and immune thrombocytopenic purpura secondary to primary cytomegalovirus (CMV) infection in an immunocompetent patient. Treatment with oral valganciclovir for 2 weeks successfully led to complete clinical recovery. CMV is traditionally associated with infection in immunocompromised patients and neonates; however, evidence of severe CMV infections in immunocompetent hosts is emerging. It is important to highlight the broad range of clinical presentations of CMV infections to prevent diagnostic delay and associated morbidity and expense.

The role of platelets in sepsis: A review

Sepsis, a life-threatening condition characterized by organ dysfunction, results from a complex series of pathophysiological mechanisms including immune dysfunction, an uncontrolled inflammatory response, and coagulation abnormalities. It is a major contributor to global mortality and severe disease development. Platelets, abundant in the circulatory system, are sensitive to changes in the body's internal environment and are among the first cells to respond to dysregulated pro-inflammatory and pro-coagulant reactions at the onset of sepsis. In the initial stages of sepsis, the coagulation cascade, inflammatory response, and endothelial tissue damage perpetually trigger platelet activation. These activated platelets then engage in complex inflammatory and immune reactions, potentially leading to organ dysfunction. Therefore, further research is essential to fully understand the role of platelets in sepsis pathology and to develop effective therapeutic strategies targeting the associated pathogenic pathways. This review delves into the involvement of platelets in sepsis and briefly outlines the clinical applications of associated biomarkers.

Pathophysiology of Disseminated Intravascular Coagulation in Sepsis: A Clinically Focused Overview

Sepsis is a major global health problem that results from a dysregulated and uncontrolled host response to infection, causing organ failure. Despite effective anti-infective therapy and supportive treatments, the mortality rate of sepsis remains high. Approximately 30-80% of patients with sepsis may develop disseminated intravascular coagulation (DIC), which can double the mortality rate. There is currently no definitive treatment approach for sepsis, with etiologic treatment being the cornerstone of therapy for sepsis-associated DIC. Early detection, diagnosis, and treatment are critical factors that impact the prognosis of sepsis-related DIC. Over the past several decades, researchers have made continuous efforts to better understand the mechanisms of DIC in sepsis, as well as improve its quantitative diagnosis and treatment. This article aims to provide a comprehensive overview of the current understanding of sepsis-related DIC, focusing on common causes and diagnoses, with the goal of guiding healthcare providers in the care of patients with sepsis.

Platelet role in the prediction of MIS-C severity

Introduction

Multisystem inflammatory syndrome in children (MIS-C) has been reported as one of the cytokine storm syndromes associated with COVID-19. Despite the several proposed diagnostic criteria, MIS-C remains a diagnostic and clinical challenge. Recent studies have demonstrated that platelets (PLTs) play a crucial role in COVID-19 infection and its prognosis. This study aimed to investigate the clinical importance of PLT count and PLT indices in predicting MIS-C severity in children.

Patients and methods

We conducted a retrospective single-center study at our university hospital. A total of 43 patients diagnosed with MIS-C during a 2-year period (from October 2020 to October 2022) were included in the study. MIS-C severity was evaluated according to the composite severity score.

Results

Half of the patients were treated in the pediatric intensive care unit. No single clinical sign was associated with a severe condition, except for shock (p = 0.041). All the routine biomarkers, such as complete blood count (CBC) and C-reactive protein (CRP), used for MIS-C diagnosis were significant in predicting MIS-C severity. Single PLT parameters, such as mean PLT volume, plateletcrit, or PLT distribution width, did not differ between the severity groups. However, we found that a combination of PLT count and the previously mentioned PLT indices had the potential to predict MIS-C severity.

Conclusions

Our study emphasizes the importance of PLT in MIS-C pathogenesis and severity. It revealed that together with routine biomarkers (e.g., CBC and CRP), it could highly improve the prediction of MIS-C severity.

Prognostic factors for favorable outcomes after veno-venous extracorporeal membrane oxygenation in critical care patients with COVID-19

BACKGROUND

Patients with COVID-19 and severe acute respiratory failure may require veno-venous extracorporeal membrane oxygenation (VV ECMO). Yet, this procedure is resource-intensive and high mortality rates have been reported. Thus, predictors for identifying patients who will benefit from VV ECMO would be helpful.

METHODS

This retrospective study included 129 patients with COVID-19 and severe acute respiratory failure, who had received VV ECMO at the University Medical Center Regensburg, Germany, between 1 March 2020 and 31 December 2021. Patient-specific factors and relevant intensive-care parameters at the time of the decision to start VV ECMO were investigated regarding their value as predictors of patient survival. In addition, the intensive-care course of the first 10 days of VV ECMO was compared between survivors and patients who had died in the intensive care unit.

RESULTS

The most important parameters for predicting outcome were patient age and platelet count, which differed significantly between survivors and non-survivors (age: 52.6±8.1 vs. 57.4±10.1 years, p<0.001; platelet count before VV ECMO: 321.3±132.2 vs. 262.0±121.0 /nL, p = 0.006; average on day 10: 199.2±88.0 vs. 147.1±57.9 /nL, p = 0.002). A linear regression model derived from parameters collected before the start of VV ECMO only included age and platelet count. Patients were divided into two groups by using receiver operating characteristics (ROC) analysis: group 1: 78% of patients, mortality 26%; group 2: 22% of patients, mortality 75%. A second linear regression model included average blood pH, minimum paO2, and average pump flow on day 10 of VV ECMO in addition to age and platelet count. The ROC curve resulted in two cut-off values and thus in three groups: group 1: 25% of patients, mortality 93%; group 2: 45% of patients, mortality 31%; group 3: 30% of patients, mortality 0%.

Vertebral Bone Marrow Clot towards the Routine Clinical Scenario in Spine Surgeries: What about the Antimicrobial Properties?

Exploring innovative techniques and treatments to improve spinal fusion procedures is a global challenge. Here, we provide a scientific opinion on the ability of a vertebral bone marrow (vBM) clot to provide a local combined delivery system not only of stem cells, signaling biomolecules and anti-inflammatory factors but also of molecules and proteins endowed with antimicrobial properties. This opinion is based on the evaluation of the intrinsic basic properties of the vBM, that contains mesenchymal stem cells (MSCs), and on the coagulation process that led to the conversion of fibrinogen into fibrin fibers that enmesh cells, plasma but above all platelets, to form the clot. We emphasize that vBM clot, being a powerful source of MSCs and platelets, would allow the release of antimicrobial proteins and molecules, mainly cathelicidin LL- 37, hepcidin, kinocidins and cationic host defense peptides, that are per se gifted with direct and/or indirect antimicrobial effects. We additionally highlight that further studies are needed to deepen this knowledge and to propose vBM clot as multifunctional bioscaffold able to target all the main key challenges for spinal fusion surgery.

The Frequency and Patterns of Post-COVID-19 Vaccination Syndrome Reveal Initially Mild and Potentially Immunocytopenic Signs in Primarily Young Saudi Women

Vaccination is the most promising approach for ending or containing the SARS-CoV-2 pandemic. However, serious post-COVID-19 vaccine reactions, including immunocytopenia (ITP) syndrome, have been increasingly reported. Several factors cause increased risks including multiple doses, age-dependent heterogeneity in immune-responses, platelet cross-reactions with microbial components, and Long-COVID syndrome. Thus, in the absence of widely available specific therapeutics, vigilance is important while more studies are needed. Using a structured questionnaire sent to different regions in Saudi Arabia, we conducted a comprehensive investigation on the frequency, rates, disease patterns, and patient demographics of post-COVID-19 vaccine side effects on febrile patients after administration three major vaccines. Results indicated that the majority of respondents administered Pfizer BioNtech vaccine (81%, n = 809); followed by AstraZeneca (16%, n = 155); and Moderna (3%, n = 34). Overall 998 participants, 74% (n = 737) showed no serious symptoms; however, 26.2% (n = 261) revealed typical syndromes. In a focused group of 722 participants, the following rates were identified: shortness of breath (20%), bruises or bleeding (18%), inattention (18%), GIT symptoms (17.6%), skin irritation (8.6%), and anosmia and ageusia (8%) were the most prominent among those who showed typical symptoms. The onset time was mostly between 1–3 days in 49% (n = 128), followed by 4–7 days in 21.8% (n = 57), 8–14 days in 16.5% (n = 43), and more than a month in 12.6% (n = 33). The onsets occurred mostly after the first, second, or both doses, 9%, 10%, and 7% of participants, respectively. The frequency of symptoms was significantly higher after Moderna® vaccine (p-value = 0.00006) and it was significantly lower in participants who received Pfizer (p-value = 0.00231). We did not find significant difference in symptoms related to differences in regions. Similarly, the region, age, sex, education, and nationality had no influence on the dose and onset timings. The findings of this study have significant clinical implications in disease management strategies, preventive measures, and vaccine development. Future vertical studies would reveal more insights into the mechanisms of post-COVID-19 vaccine syndrome.